Restrictions to a commercial learner's permit or commercial driver license shall be as follows: (1) L--Operation only of a commercial motor vehicle which is not equipped with air brakes; (2) M--Operation only of a Class B and C commercial passenger vehicle; (3) N--Operation only of a Class C commercial passenger vehicle; (4) W--Operation only of a restricted CDL; (5) V--Operation only if driver has received a medical variance that allows the driver to be issued a medical certificate; (6) E--Operation only of an automatic transmission commercial motor vehicle; (7) K--Operation only if driving intrastate; (8) O--No operation of a tractor-trailer commercial motor vehicle; and (9) Z--No operation of a fully air brake equipped commercial motor vehicle. Source: SL 1989, ch 267 , § 18; SL 1996, ch 201 , § 2; SDCL § 32-12-98; SL 2001, ch 171 , §§ 90, 115; SL 2011, ch 144 , § 7; SL 2015, ch 168 , § 19.